The field of the invention relates generally to vascular catheters.
Vascular catheters are surgical implements used to deliver, among other devices, vaso-occlusive devices. Vaso-occlusive devices are used to occlude sites in the human vasculature, such as an aneurysm. Typically, the catheter is guided into position through the patient""s vasculature using a guidewire. Once the guidewire is guided to the desired site in the vasculature, the catheter is advanced over the guidewire so that the distal end of the catheter opens to the desired site in the vasculature.
With the use of such over the wire catheters, the guidewire needs to extend a sufficient distance outside of the patient""s body to enable the catheter to be threaded onto the guidewire without disturbing the positioning of the guidewire. Typically, a guidewire extension is attached to the proximal end of the guidewire in order to provide the additional length necessary to thread the guidewire into the catheter. The typical catheter ranges in length from 120 cm to 160 cm. Therefore, the guidewire extension can be quite long and awkward to manipulate as it extends outside the patient""s body. This may require an additional medical assistant to solely monitor or manipulate the guidewire.
An alternative catheter design is the xe2x80x9cmonorailxe2x80x9d or rapid exchange variant of the over the wire system. The rapid exchange or xe2x80x9cmonorailxe2x80x9d catheter has a first lumen running the length of the catheter and a second shorter lumen located at one end. The guidewire is threaded through the second shorter lumen at the end of the catheter, which acts as the xe2x80x9cmonorail.xe2x80x9d Because the lumen is quite short, only a short length of guidewire needs to extend outside the patient""s body, thus allowing a single operator to guide the catheter over the wire without the need of an assistant.
A variation of this rapid exchange design is to provide a slit or opening in the wall of a single lumen catheter a short distance from the distal end of the catheter. The guidewire then passes through the lumen of the catheter and out this slit or opening, such that only a small portion of the catheter is over the guidewire. While this design allows for easy exchange of the guidewire in the catheter, it is not desirable for delivery of vaso-occlusive devices because the vaso-occlusive device may exit out of the slit or opening instead of through the lumen of the catheter, resulting in improper placement of the vaso-occlusive device.
Thus, there is a need for an improved rapid exchange single lumen catheter that can deliver vaso-occlusive devices.
To these ends, the present rapid exchange or xe2x80x9cmonorailxe2x80x9d catheter includes a control valve adjacent to an opening in the side wall of the catheter at its distal end, which allows placement of the catheter over a guidewire while at the same time allows for delivery of vaso-occlusive devices through the lumen of the catheter. As the catheter is loaded on the guidewire, the control valve directs the guidewire out of the lumen of the catheter. Once the catheter is positioned at the appropriate site in the vasculature, the guidewire is removed and a vaso-occlusive device is loaded into the catheter. As the vaso-occlusive device is pushed through the catheter to the desired site, the vaso-occlusive device forces the control valve to close, which prevents the vaso-occlusive device from exiting through the opening in the side of the rapid exchange catheter.
Other and further aspects and features of the invention will be evident from reading the following detailed description of the drawings, which is intended to illustrate, but not limit, the invention. The invention resides as well in sub-combinations of the features and steps described.